Internal-combustion engine.



WKK. THOMAS.

INTERNAL GOMBUSTION ENGINE.

APYLIOATION FILED DBo.e,1911.

LQELQ, Patented Jan.21,1913.

roei, Tse.;y

To allaowm it concern: v L Be 1tI known that I, lVALrnR K. THOMAS, a

Acitizen of the United States, residing in the borough of Brooklyn, in -tlie cityy of New p thereof.

My invention 'relates to internal combustion engines, 'and' more particularly to a type of four cycle. valveless engine.`

The main object of the invention is to provide an] internal co-mbustion engine ofv the 'four cycle type wherein thel cylinder Will have nonioving parts therein except- -ngthe p'iston,' and wherein the manner of .introducing the explosive charge will be Such as to `secure high efhciency and the eliminationl of likelihoodvof the firing of an explosiveI charge before its entrance to the cylinder.l i

further .objectis,to` pro-vide an engine s of the vpiston be filled with Uas,thus avoiding firing across eriobject is to provide an cylinder scavenged after each explosion,y @infr to each introductionl of the explosive mixture thereto; so as to m1ni "inize the vvolume of exhaust gasesin the cylinder, to secure a pure mixture in said cylinder, and to prevent the rapid fouling of said cylinder.

A still further object engine of the 'four cycle type wherein after each explosion a scavenging charge is introducedl to the cylinder under conditions whichfwil-l rcushion Ithe piston' upon the upstroke succeeding the explosion' stroke,-

thusfminimizin'g vibration in the engine,

i i Y and' serving to more completely scavenge the cylinder, and` at the saine. time aid in cooling the cylinder.

Alnstillfurther.object is to prfhividejan'l engine-ofthe vfourv cycle type utilizing a vsca venging charge.

A still further object is to provide an engine of the four cycle type wherein the in'- 'INTimiiAL-c'oiviietis'iioii ENGINE ,typte.,wliehreineach charge will be ipressed bythe movement ofy the iston prio'-towits introduction to the cylinder, and 'wherein at-fno` time will the space on is to provide an TED STATES.; "PATENT z,ot/irmii., F

n El; K. THoMAs, oF NEWYfojrK, rijst., Assioivon rio Hyvisiitrfns TRUSTEE take and exhaust ports will be controlled solely/through the movement of the pistonl itsel/t and the valve mechanism for regulating the supply yof explosive mixture willbe` removed from` the area of high temperatures about the cylinder so as to avoid the heat'- ing of the valve mechanism and permit.' the use of a` rotary valve without subjecting it A still further object is to provide a siin- I ple and convenient means of communication .between said valve mechanism and the carbureter, or other source of Supply for the explosive mixture. And a Astill further object is to provide an engine of this type, the' design of which will be simpleand such as l.

to permit of ready access thereto for pur-` poses of inspection or repair.

The invention `consists primarily in an engine of the four cycle type, embodying therein a. cylinder having an inletand an outlet port adjacent to. one end thereof, a reciprocatory piston adapted, toward the end of the stroke, toopen said exhaust port and said intakeport successively, means ,forming achamber in communication with said intake portand subject to pressure from a piston, and a valve mechanism for introducing the lexplosive mixture to said, ychamber during -the fourth stroke of the cycle,"said valve mechanism being so set as to exclude the explosive mixture from )said chamber during the compression andielxf` plosion strokes of the engine; and in such other `novel features of construction and combination of parts` as yare hereinafterset, forth and describedr and more particularly, pointed 'out in the-.claims hereto appendc-d.

Referring to the drawings: Figure l is an elevation of a four cylinder engine embody--. viiigmy inventiorr;A Fig; 2,is a vertical sectionthroughl one of the cylinders thereof; Fig is a section of the `valve mechanism on the line 3 3 of- Fig. l, on an enlarged scale; and Fig. '4 is a detail sectional view shown in the drawings, a indicates a cylin-v der casting having a removable head -b and provided with the ordinary water jacket c.

The engine shown in the drawings 1s of the four cylinder type, although the number. of

cylinders is immaterial to my invention.

For convenience in describing the mode of operatlon of the valve mechanism, I'have indicated the cylinders in their order of actuation by the reference numerals 1, 2, 3 and 4, but 'in the following description will refer.

to the detailed arrangement of but one such cylinder, as all said cylinders are alike in every respect.

Each cylinder has mounted therein Van ordinary reciprocatory piston d connected in the usual manner by a piston rod d with its crank e on the shaft e. The details of these parts may be in accordance with any approved practice in connection with internal combustion engines, and are immaterial to this invention.

To avoid the necessity vfor a suction stroke of the piston andalso to avoid the presence of an intake valve about the heated portions of the engine, I provide means in conjunction with each cylinder, forming a chamber wherein theldown stroke of the piston will compress a charge and prepare it for introduction into the cylinder at a predeter-v f mined moment as determined by the movement ofthe piston in its stroke. Each cylinder is provided adjacent to one end thereof with an intake port f arranged so as to be normally closed by the piston d and to be Opened only as said piston approaches the limit of its stroke, sald port being in com munication with said chamber through an uninterrupted duct f so as to permit the explosive mixture under compression to flow 'prises two concentric tubes m and n, the 1ninto said cylinder as said intake port is opened through the movement of said pist0n. The piston dV on the top thereof adjacent to the said intake port f, is provided with a defiector plate d2 adapted to cause the inowingmixture to be directed toward the cylinder head, in the manner ordinarily employed in 'two-cycle engines.

In order to simplify the design of the engine, particularly in small units, I preferably use the crank casing as the compression chamber above referred to, this arrangement lending compactness of structure,'and this type of engine permitting the use of a. crank case of a capacity approxi? mating that of the cylinder itself. Carrying out this preferred structure, I provide' a flanged crank case casting g bolted to lof the crank casethroughcut from the onboth si the. cylinder casting a, having therein a plurahty ofvcrank cases g', g2, g, g, forming independent, non-communicatin com ression chambers each having 1 ing erefrom a duct f. These cases g', g?, ga d gf, are split in the usual manner-to form -bearm or the shaft e. 'Each said case is provi ed with-a bottom hand hole closed by a plate h to permit convenient access to the Y crank and piston connection.

Each compression chamber is provided with a valve mechanism controlling the flow of the mixture from the carbureter, or other ysource of supply ofthe explosive mixture= thereto, which mhanism is so actuated as .to admit suchfmixture to. each chamber but once during two rotations of the shaft e, thus avoiding all those dangers resulting presence of an explosive mixture es of the piston at the same time. To equalize thepressures`in front of the piston on both the'direct and the return reciprocation thereof, I preferably so arrange this valve mechanism as to alternately deliver to said chamber an explosive and a non-explosive fluid with the successive rotations of the shaft e, thus not only securing the desired cushioning effect, but permitting the use of the non-explosive liuid as a scavenging charge in a manner. which will hereinafter appear.

To simplify the valve mechanism above referred to, I prefer to use a casing f'. extending the entire length of the casting a and having laterally elongated narrow ports i', 2, 3 and t", opening into the compression chambers formed within the crank cases g', g2, g3, g. This casing or housing i has a longitudinal cylindrical bore and rotatably mounted therein is a rotary valve actuated from the shaft e by a single chain and sprocket mechanism j arranged at one end of the casing. Extending circumferentially about a portion of the casing or housing i is a conduit c opening into which is the lead pipe from the carbure-ter Z.

The rotary valve above referred to comner of which, is closed at one end only and opens at the other end into atmosphere, and the other of which (m) is closed at both ends, (see Fig. 3.) The tube m has a plurality of gas ports m', m2,' m3, 'm4 extending therethrough and adapted to regisv also has a plurality of air ports n', n2, as, 12,4-,

similar in their arrangement and dimensions .to the gas port acting in conjunction with the same port in the casing or housing i.

These lports `nfmn't, n3, n4 are adapted to reg1stervvith'the ports i, 2, 2'?, if through short gas-tight tubes,f(see Fig., 3) which also serve as stays for the tubes m land n.

tube is 'constantly incommunication. `W1th the condult' 7e through oney or more ports c in said tube, which with the open endfof the tube `n results in a structure wherein the valve mechanismv itself serves I in theI ratio of 2 to l.

as a manifold. This lvalve arrangement is adapted for use inl connection With a driving means actuated from the main shaft, the valve bein'gg'eared down from said shaft At the end of the cylinder adjacent to the port'f, Iform an exhaust port o in communication with the exhaust manifold 79. The port o is adapted to be opened andclosed through the reciprocatory `movement ofthe pistona. This port is arranged suiiiciently inI advance 4of the'intake port f to insure the' ing a to facilitate the removal of the piston.

I preferably use a splash system of lubrication, and in, order to maintain the oil level Within thercrank case, I previde each case With a drain pipe r projected to a predetermined height Within said case, which pipe is controlled by the pet cock r.

ITo take `advantage of .the engine lubri- I eating system, I position the ports'z", 2, 3, t

so that oil Will be thrown4 therethrough upon the up stroke of the crank e. Between adjacent sets of gas and air ports m nl', m2 n2, etc., `I encircle the tube m With grooves s, adapted to retain lubricant and at the same time fluid Vpack said tube.

The capacity of the compressionV chambers,-inorderto1secure an effective compression vof vthe fluid delivered thereto, whether the same be an explosive mixture, oratmospheric air, must be limitedI so as to approximate thatlofvthe cylinder.y `Vhen I utilize the crank @ses g" g2, `g3 gt to form these compression. chambers, Ilimitfthey ca pacityi thereofviorvr the purpose above referred to by forming ,Within thepiston al an vinner shell El adapted to completely clo-se `the .bottom of saidpiston, leaving only achannel adapted to permit t-he oscillatory movement; ofr-,thepiston rod, and mount u`pon-each side of the crank fc ansolid dlsk -ezoccupying 1 a considerable portion of. the

spacewithin said casing, leaving only clear-h .f ance enough to permit the'movement-'of` ,the, pistonfrod and at the saine time clearance on the lside of said disks suiicientto admit l the tluiddrawn Within said case. By this means Ireduce the capacity of the ordinary crank case `to a degree Where I amenabled to develop approximately thirty pounds pressure Within the case. .This-results in economy in the operation of the engine, as

but a very small portion 0f the iiuid will remain in the casing after each charge has been dellvered to the cylinder. i

The operation of the herein described in-` i ternal combustion engine is substantially vas follows In describing the mode of operal tion of my improved engine, I yWill do so A assuming that thevparts are in the relation shown in the'drawings, in Whichthe piston of cylinder 1 lhas reached the limit v'of'its fourth stroke of the cycle. As said' piston makes its up or suction stroke, it Will drawv theexplosive mixture through the ports m and, t" into the compression chamber, Awhich' inthe form of the invention shown in the a n 'l drawings, comprlses the crank case g. This f suctionlvill dran the mixture from the-car-` bureter Z through the tube m, and the port or ports k therein in constant communica` A, ,95 mg down stroke of the piston of the-cylmH tion With the conduit la. With lthe succeedfg der l, the explosive charge drawn into'jthe said compression chamber or case g will be compressed 1n said chamber and as said cylinder opens the portf, this mixturefunder` a pressure of about 30 pounds Will be 'ad'-I mitted to the cylinder l through the conduit 4 f and port f. Upon the succeedin u ,or g P compression stroke of the piston, this charge will bezsupressed yin the cylinder and igie, nited to produce the explosion stroke of theV pist-ou. As the said piston begins its compression stroke, and after it closes the porif f, the `valve port n' Will come to register with the port 2" and the suction created Within the compression chamber or crank case g will dravv air through the tube A1i into said case and this 'air Will be compressed inY said chamber vor case upon the explosion stroke of the engine so that during the'compressionjstroke and during the explosion stroke of the eigine, said compression ehamber will contain a non-explosive fluid, thus making tiring across the piston impossible.`

l/Vhen the piston has reached the limit of its compression stroke, the charge Will bel i.gnited, and the explosion stroke will -follovv.

wWith the third stroke of the piston, the scavenging charge in the compression cham-` ber or case g -Will be compressed and after the port o has been opened to permit the escape of the exhaust gas, the intake portf'f will be opened and the scavenging charge under pressure Will be admitted to the cylinder, the ,deflector plate Z2 uponI the piston los i pmjecting this charge upwardly so as to .cause the air to displace the exhaust gas near the cylinder head and thus aid in the escape ofthe exhaust gases. While there will not be a'icomplete exhaustion of these gases, those remaining will be so diluted as to minimize thequantity of inert gas in the cylinder.

completes the fourth cycle of the ene aspthe succeeding stroke ofthe piston 1g v1s* the suction stroke, or first stroke of the v c cle.

- arge thus introduced tothe cylinder is l the top During this stroke, the scavenging compressed therein and upon the succeeding down or intake stroke this scavenging charge is-permit-ted to escape through the opening of the vport o which esca-pe is accelerated by the deflection of the incoming explosive mixture by the detlector plate d2 toward of the cylinder.

The .cycle of the engine is divided into foul; strokes, as follows rst, suction of explosive charge into compression chamber,

land compression of scavenging charge in thereto the added function of a scavenging of the cylinder prior to the introduction thereto of each explosive charge. Furthermore, I am enabled'to deliver the explosive charge to the cylinder under pressure devcloped by the piston itself, avoid the presence of any vacuum in the cylinder, and in addition to providing a cushion upon both sides of the piston at all times, secure a more perfect exhaustion of the inert gases after the explosion stroke. By this construction, I am enabled to arrange my valve mechanism away from the heated cylinder so as to avoid any possibility of the fouling or binding thereof by the carbon particles or the high temperatures.

While I prefer to use a rotary valve such as I have shown and described, it is not my intention to limit the invention in its broader aspects to a valve mechanism of this.v type. This construction, however permitsA a perect timing ot the intake of the explosive charge and the scavenging charge, as to all cylinders included in the unit, and for engines of low H. l). it is found very desinble.

The engine cycle above described/ relates $5 to a single cylinder, but each cylinder will operate` in this cycle, the order followed ordinarily being cylinder 1 first, then cylinders 2,3 and 4 successively.

.When using a crank case as a compress1on chamber by reducing the capacity thereof 1n the manner described, I am enabled to secure the desired high pressures of the charges prior `to admission to the cylinder to insure a sufficient-ly large discharge into the cylinder to avoid Waste, or a poor mixture, of the gaseous charge, WhileA at the same time avoiding the presence of suicient gas in the scavenging charge to produce an explosive mixture. The ports f and o areV so positioned, and the valve mechanism so set, as to insure that lead necessary to secure the proper exhaustion of the gases in the cylinder.

Then I use a rotary valve, such as I have described, the grooves svwill prevent leakage from one port to the adjoining port, and the oil thrown through the ports z" 2 3 and i* will lubricate said valve-tube to the desired extent. 'El

lVhile the compression ot the explosive charge in the compression chamber and of the scavenging charge in the cylinder Will tend to place slight additional load upon the engine, this load Will be compensated for by the expansive force of said scavenging charge While the explosive charge is being compressed.

The detailed construction shown is merely for convenience in assembling, inspection and repair.

It is not my intention to limit the invention to the precise details of construction shown in t-he accompanying drawings, it. be-

ing apparent that such may be modified Without departing from the spiritor scope of the invention.

Having described my invention, what I claim as new and desire to have protected by Letters Patent, is

l. An'internal combustion engine of the four cycle type, embodying therein a cylinder having an intake and an exhaust port adjacent to one end thereof, a reciprocatory piston, adapted, toward the end of the stroke, to open said exhaust port and said intake port successively, means forming a chamber in communication with said intake port and subject to pressure from the piston, and a valve mechanism for introducing the explosive mixture into said chamber during one stroke vof the cycle, said valve mechanism being so set as to exclude the explosive mixture trom said chamber during the compression and explosion strokes of thepiston.

2. An internal combustion engine of the our cycle type, embodying` therein a cylinder having an intake and an exhaust port adjacent to one end thereof, a crank case incommunication with said cylinder through llt said intake port, a reciptcry piston adapted, toward the end lof the stroke, to open saidexhaust port and said intake port successively, and a valve mechanism for introducing an explosive mixture into said crank case during one stroke of the cycle, said valve mechanism being so set as to exclude the explosive mixture from said case during the compression and explosion strokes of the piston, whereby said explosive charge will be compressed in said crank case by the piston, and firing across'the piston is prevented.` f

3.'An internal combustion engine of the four cycle type, embodying therein a cylinder having an inlet and an outlet port adjacent to one endthereof, a vcrank case in communication with said cylinder through said intake port, means limiting'- the capacity ofsaid crank case to substantially that of said cylinder, a reciprocatory piston, adapted, toward the end of the stroke, to open saidl exhaust port andv said intake port successively, and la valve mechanism for introducing an explosive mixture to said crank case "during one stroke of the cycle, said valve ral during the compression and mechanism being so set as to exclude the explosive mixture from said case duiin the compression and explosion strokes o the piston,hwhereby said explosive charge will be compressed in said crank case by the piston, and firing across the piston is prevented.

4. Anginternal combustion engine of the four cycle" type, embodying therein a cylinder havingan intake and an exhaust port adjacent to one end thereofa reciprocatory piston, adapted, toward the end of the stroke to open said exhaust port and said intake port successively, a deHector plate upon the top .i of said piston whereby the incoming duid is directed toward the cylinder head, means yforming a chamber in communication With piston, means forming a chamber in communication with said intake port and subject to pressure from the piston, and a valve mechanism: adapted to alternately deliver a charge of an explosive, ymixture anda charge 'to said chamber, whereby `said` charges will be alternately compressed and delivered n to `said cylinder through said intake port, and said piston will never have an explosive iluid upon both es thereof at the same time.

in internal combustion engine of the four cycle type, embodying therein a cylinder having an intake and an exhaust port adjacent to one end thereof, a reciprocatory piston adapted through its movement to automatically open and close said ports, means forming a chamber in communication with said intake port and subject to pressure from the piston, and a valve mechintake port, and said piston` will never havev an explosive Huid upon both sides thereof at the same time. 'e

7. An internal combustion engine of the four cycle type, embodying therein a cylinder having an intakeand an exhaust port adjacent to one end thereof, a reciprocatory piston, a crank case communicating with saidcylinder through said intake port and with said cylinder below said piston whereby gases therein contained will be compressed by said piston and delivered to said cylinder, and a valve mechanism adapted to alternately deliver a charge of an explosive mixture and a scavenging charge to said chamber, whereby said charges Will be.

alternately compressed and delivered to said cylinder through said intake port, and said piston will never have an explosive fluid upon both sides thereof at the saine time.

8. An internal combustion engineof the four cycle type, embodying therein a cylinder having an intake and an exhaust port adjacent to one end thereof, a reciprocatory piston, a crank case communicating with said cylinder through said intake port and with said cylinder below said piston Whereby gases therein contained will be compressed by said piston and delivered to sa-id cylinder, means limiting the capacity of said crank case to substantially that of said cylinder, and a valve mechanism adapted to alternately deliver a charge of an explosive mixture and a scavenging charge to said chamber, whereby said charges will be alternately compressed and delivered to saidv cylinder through said intakeV port, -and said piston will never have an explo-sive fluid upon both sides thereof at the same time.l u

9. An internal combustion engine of the' four cycle type, embodying therein a cyl1nder having an intake and an exhaust port' adjacent to one end thereof, a piston, adapted toward the end of the stroke, to open said exhaust port and said intake port successively, means forming a chamber in communication with 4said intake port and subject to pressure from a piston, and avalve mechanism for introducing the explosive mixture to said chamber duringv one stroke of the cycle, said valve mechanism being titi lll() vso set as to exclude the explosive mixturel from 'said chamber during the compression and explosion strokes of the piston. 10. An internal combustion engine,fof the 5 four cycle type, embodying therein a' cylinder-having an intake and an exhaust port adjacent to one end thereof, a piston, means forming a chamber ,in communication with said intake port and subject to pressure from the piston, and a valve mechanism adapted to alternately deliver a charge of an explosive mixture and a scavenging charge to 'said chamber, whereby saidcharges will be alternately compressedand delivered to said cylinder through said intake port, and said piston will never have an explosive fluid uponboth sides thereof at the same time.A

11.' An internal combustion engine of the 42i0 four cycle type, embodying therein 'a plurality of cylinders, each having an intake and an exhaust port'adjacent to one end.

thereof, a reciprocatory piston adapted to- -ward the end of the stroke toopen said exhaust port and said intakev port successively,

mounted in each cylinder, means forming Aa plurality of non communicating chambers in communication with said intake ports and;

subject to pressure from said pistons re- '30 'spectively, and a valve mechanism'for introducing an explosive mixture to each said chamber during onestroke of the cycle as to its cylinder,v said valve mechanism being so set as to exclude the explosive mixture from its chamber during the compression and explosion strokes of the piston.

12. An internal combustion engine of the four cycle type,'embodying therein a plurality of cylinders, each having an intake 40 and an vexhaust portadjacent to one end thereof, a reciprocatory piston adapted toward the end of the stroke to open said exhaust port and said intake port. successively, mounted in each said cylinderfmeans forming a plurality of non` communicating chambers in communication with said intake` ports and.subject to pressure from said pistons respectively, andv a valve mechanism common to all of said cylinders, for introducing an -explosive mixture .to each said chamber during one 'stroke of the cycle as to its cylinder, said valve mechanism being so set as to exclude the explosive mixture from its chamber during thecompres- .55 sion and explosion strokes of thepiston.

13. An internal combustion engine of the four cycle type, embodying therein a cylinder having an intake and an outlet port adjacent to one end thereof, a crank case 6.0 in communication with said cylinder `through said intake port, a reciprocatory piston, adapted, toward the end of the stroke, to open said e'xhaust port and said intake port successively, and al valve mechanism carried by said crank case, `whereby it v adjacent to one end thereof, a crank casein communication with saidvcylinder through said intake port,\`l a reciprocatory piston", adapted, toward the end'of the st-roke, to open said exhaust port and said intake port successively, and a valve mechanism carried by said crank case,'whereby it is re- .35. moved from the area of high temperatures, for introducing an explosive mixture to said crank case during one --stroke of the cycle, embodying therein a casing 'having a port opening into said crank case,- and a rotary valve comprising concentric tubes' having ports therein adapted to successively .register with said port in said'casing, said tubes respectively opening into atmosphere and communicating with a source of fuel supply, .95 said valve'` mechanism being so as to. exclude the explosiver mixture from' and introduce air .to said case during the compression andexplosion strokes of the piston', whereby said explosive charge will be 100 -compressed in said crank case by the :piston and firing across the piston is prevented,

15. An internal combustion engine of the four cycle type, embodying therein a plurality of cylinders, Aeach havingan intake .105 and an exhaust f port :adjacent to one end thereof, va plurality'of non communicating crank cases in communication severally with .a cylinder through the intake port thereof,

a reciprocatory piston in each cylinder, .110 adapted toward the end of the stroke to open said exhaust port and said intake port successively, and a valve mechanism for 1ntroducing an explosive mixture to said crank cases, embodying therein a.l casing having ,115

ports opening intov said crank cases respectively, and a rotary valve mounted in said casing comprising a plurality of concentric tubes having continuous ducts therein, vand a plurality of ports adapted to successively 120 register with said ports in said casing, one

of said tubes opening into atmosphere, and the `other said tube having ports therein whereby a fuelvsupply is introduced thereto, and means carried by said casing whereby '125 said last named ports are alwaysin communication .with the carbureter lead pipe, said valve mechanism being 4so set as to exclude the explosive mixture from, and in-y troduce air into and compress it in said cases during thtf'compression and explosion strokes of"the"pistons, whereby said 'explosive charge will be compressed in said l"crank cases by the p istons, and liring across the pistons is prevented.

l 16. An internal combustion engine of the four cycle type, embodying therein a plu'- rality of cylinder s, each having an intake and `an exhaust port adjacent to one end traduce air into and compress it in said thereof, a plurality of non communicating crank cases `in communication severally with.

a cylinder through the intake port thereof, a reciprocatory pist-on in each cylinder, adapted, toward the end ofthe stroke to open said exhaust port and said intake port successively, and a valve mechanism for introducing an explosive mixture to said crank cases, embodying thereina casing having ports opening into said crank cases respectively, and a rotary valve mounted insaid casing, comprising a plurality of concentric tubes having continuous ducts therein, and a plurality of ports'adapted to successively register with said ports in said casing, one

4of said tubes opening into atmosphere, 'and the'other said -tube having 'ports' therein whereby a fuel supply is introduced thereto,

ymeans forming a continuous duct partially' encircling said casing and opening inwardly thereof andA adapted to communicate continuously with said ports in the gas tube,

said valve mechanism being so set as to exclude the lexplosive mixture from, and incases during the compression. and explosion strokes of the pistons, whereby said yexplosivecharge will be compressed in said crank cases by the pistons, and firing across the pistons is prevented. i

17. An internal combustion engine of.. the four cycle type, embodying therein a,eylin -der having4 an intake and anexhaust port adjacent to'one end thereof, a reciprocatory piston, closed at the bottom and adapted toward the end of the'stroke to open said .exhaust port andl said intake port successively, means forming a chamber in. communication with said cylinder, through said intake tport, and a valve mechanism for initroducing the explosive mixture to 'said chamber during the first stroke of the cycle;

in communication with said cylinder, at the bottom thereof and through said intake port, a crank shaft mounted in said case, aV recifprocatory piston adapted toward 4the end o the stroke to open said exhaust port and said intake port successively, a piston rod, disks mounted upon and rotatable with said crank shaft and reducing the capacity of .said case, and .a valve mechanism for introducing the explosive mixture to said crank] 'case during the first stroke ofthe cycle,said

valve mechanism being so set as to exclude the explosive mixture from said case during vthe compressipn and explosion strokes of the piston,

In witness whereof, I have hereunto affixed my signature, in the presence of two subscribing witnesses, this 1st day of December, 1911. v .WA-LTER K. THGMAS.

i/Vitnesses:

' T. T. l/VENTWORTH, EUGENE vVENiNa c 

